Answer: a) 278 * 10^-12 F and 19.4 * 10^-9 C
b) 17.44 * 10^3 N/C and c) C=k*C0 and V=70/k
Explanation: In order to solve this problem we have to use the expression of the capacitor of parallel plates as:
C=A*ε0/d where A is the area of the plates and d the distance between them
C=Π r^2*ε0/d
C=π*0.2^2*8.85*10^-12/0.004=278 * 10^-12F= 278 pF
then
ΔV= Q/C
so Q= ΔV*C=70V*278 pF=19.4 nC
The electric field between the plates is given by:
E= Q/(A*ε0)=19.4 nC/(π*0.2^2*8.85*10^-12)=17.44 *10^3 N/C
If it is introduced a dielectric between the plates, then the new C is increased a factor k while the potential between the plates decreases a factor 1/k.
Answer:
6kg
Explanation:
According to conservation of kinetic energy
m1u1+m2u2 = (m1+m2)v
m1 and m2 are the masses of the bodies
u1 and u2 are the initial velocities
v is the final velocity
Given
m1 =2kg
u1 = 8.0m/s
m2 = ?
u2 = 0m/s (second ice at rest)
v = 2.0m/s
Substitute into the formula
2(8)+m2(0) = (2+m2)(2)
16+0 = 4+2m2
16-4= 2m2
12 = 2m2
m2 =12/2
m2 = 6kg
Hence the mass of the second block is 6kg
kinetic energy is being transferred to gravitational potential energy
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